The overall objective of this project is to determine whether significant advantage can be obtained from internal fixation of diaphyseal fractures using plates made of newly developed materials. Specifically, the goal is to determine whether a fixation plate that has a modulus of elasticity closely matched to that of bone but with greater fracture strength than bone can be shown to have advantages in preventing osteopenia caused by the conventional rigid metal plates which have a modulus of elasticity more than ten times greater than that of bone. Materials to be used in the construction of the fixation plates are composite materials Graphite Fiber-Methylmethacrylate, Graphite Fiber- Surgical Epoxy, and Filament Wound Chemical Vapor Deposited Carbon. The plates developed will be applied to standard transverse radial and femoral osteotomies of dogs. Tetracycline will be used to identify bone formed during the remodelling which occurs during the 16 weeks prior to sacrifice. Comparisons between stainless steel and vitallium plated fracture fixation and composite plated fracture fixation will be made on clinical, biocompatibility biomechanical, and quantitative histological criteria.